Slide fastener



Aug' 29, 1951 A. J. MGNAMARA 2,997,766

SLIDE FASTENER Filed Jan. 8, 1959 BYMMH. w

:United States Patent O t "2,997,76 6 SLIDE FASTENER Ambrose J. McNamara, White Plains, N.Y., assignor to Irving Constant, New York, N .Y.

Filed Jan. 8, 1959, Ser. No. 785,629 8 Claims. (Cl. 24-2051) 'Ihe present invention is directed to a slide fastener and more particularly to a slide fastener which may be readily mounted abovea seam, and which permits a construction to be obtained which in its closed disposition closely sirnulates a seam.

It has long proved desirable to provide a slide fastener which can be mounted into a cloth article, and which when so mounted will closely simulate a seam when in closed disposition. A variety of approaches have been developed for the insertion of slide fasteners into cloth |articles in which the line of sti'tching joining the tapes of the slide fastener to the cloth article are closely adjacent to theelements of the slide fastener.

The pioneering researches-of Philip E. Crystal led to the development of a slide fastener whose slider and elements were the type shown in I-Iug United States Letters Patent 2,738,560 issued March 20, '1956, but which possessed an element-free gap devoid of means connecting the slide fastener tapes below the lowermost elements carried by the tapes, with bridging means connecting the tapes at their bottom.

' The aforesaid slide fastener of Philip E. Crystal permits the slider to be slid from the lowermost elements of the slide fastener onto the welts of the slide fastener tapes in the gap portion so that the slider is completely removed from the elements. Bridging means at the bottom of the slide fastener, such as a bar tack or metal clip, serve as a stop, and prevented the separation of the slider from the tapes of the slide fastener in the aforesaid slide fastener of Philip E. Crystal.

The slide fastener invented by Philip E. Crystal was the most eiiiient slide fastener of the concealed type theretofore developed.

, However, notwithstanding the superiority of the aforementioned slide fastener of Philip E. Crystal, difficulties have been encountered with its use. Thus, in the assembly of slide fasteners at high speeds, the slider is prone to become dislodged from the 'slide fastener in usage. This is a most serious difliculty, since the dslodgement of the slider canses the complete cessation of the practice of such method. In' particular, with inexperienced or careless operators, the dislodgement of the slider from the slide fastener may constitute so serious a problem as to detract from the value of the aforesaid method.

This invention has .as an object the provision of a novel slide fastener.

This invention has as another object the provision of a slide fastener which may be readily installed into a cloth article by lines of stitching which are closely adjacent to the elements of the slide fastener tapes.

Other objects will appear hereinafter.

For the purpose of illustrating the invention there is shown in the drawings a form which is presentiy preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

Referring to the drawings, wherein like reference characters refer to like parts:

FIGURE 1 is a plan view of the slide fastener of the present invention with the slide fastener elements thereof in engaged disposition, such view revealing the appearance of the front face of the slide fastener.

FIGURE 2 is a view similar to that of FIGURE 1, but revealing the appearance of the rear face of the slide fastener.

ice.

2 FIGURE 3 is a section taken on line 3-3 of FIG-" URE 2. FIGURE 4 is a section taken on line 4-4 ofv FIGf URE 2. 4 i' FIGURE 5 is a fragmentary view revealing the appear ance of the bottom portion of the slide fastener of the present invention when the elements thereof are in non-f engaged disposition. Referring to the drawings, the slide fastener 10 'of the; present invention comprises an element-carryingtape 12 having a welt 14, and an element-carrying tape 16 having a welt 1'8. Each of the tapes 12 and 16 is provided with' elements 20 which mate with each other when the slide' fastener 10 is disposed in its closed disposition, as seen` particularly in FIGURE 2. i The elements 20 comprise curved members, each of which embraces the welt of the respective tape upon` which it is carried. Thus, the welt 14 is received the elements 20 which are carried by the tape 12, and the' welt 18 is received within the elements 20 which` are carried by the tape 16. The elements 20 may be pivoted upon their supporting welts if desired, so'. that suchelements may be held erect sopas to enable a line of stitching to be placed closely adjace'nt such elements 20.V It will be seen from FIGURES 3 and 4,-when taken' in conjunction with FIGURE l, that the welts 14 and-18" are folded back and overlap the tapes 12 and 16 when the slide fastener elements 20 are engaged. Thus, as seeniinf? FIGURE 1, when the slide fastener 10 is viewed from'thei side opposite to the side on which the fastener elements 20;' are carried, such fastener elements 20 are obscured 'by't'he5 tapes 12 and- 16. This enables the slide fastener "10 to' function as a concealed slide fastener. The slider 22 rides on the inner and ou'ter edges of the elements 20 when the slider 22 is engaged with such elef' ments 20. A wide variety of constructions of slider and`I elements may be utilized in the slide'fatener 1,0 ofgthe: present invention. However, the elements and the'slideri shown in Hug United States Letters Patent 2,7378,'5'60 issued March 20, 1956, are especially suitable.

It is to be noted that the slide fastener 10 of the presentb invention is not provided with a bottom stop or clip ad? jacent the lowermost elements 20' on the tapes 12 and -16`z (see FIGURE 2). Instead, below such lowermost elei" ments 20' on the tapes 12 and 16, there is provided ,afV

gap designated 30 which is devoid of elements and which;-

has a length appreciably greater than the length of theslider 22. The gap 30 is defined by the lowermost eleJz ments 20' of the tapes 12 and 16 and the bottom clip 2 4" which joins the tapes 12 and 16 together at their bottoni" most ends. The bottom clip 24 may be a metal clip which grips the welts 14 and 18. The bottom clip 24 holds the tapes 12 and 16 in alignment, so that the elements 20 carried by such tapes 12 and 16 will mate. In place 'of the bottom clip 24, other bridging means may be utilized, such as a bar tack or the like.

The portion of the welts 14 and 18 below the bottommost elements 20' on the tapes 12 and 16, namely the portion including the gap 30, diifers from the remainder of the welts on the tapes 12 and 16, in that such bottom welt portions are stiffened by a stiifening agent 28. Referring particularly to FIGURES 3 and 4, it will be seen that the welts 14 and 18 comprise the cords 26, which in the illustrated embodiment have a circular cross-section, disposed within tubes at the innermost ends of the tapes 12 and 16. The portons of the welts 14 and 1'8 which carry the elements 20 are devoid of stilfening agent 28, as can be seen in FIGURE 4. Such Welt portions are' therefore flexible, as is necessary for the satisfactory engagement between the elements 20 carried on the tapes 12 and 16. However, as seen from FIGURE 3, and also as indicated in FIGURES 2 and 5, the portons of the welts 14 and 18 below the lowermost elements 20' are relatively rigid although still possessing some flexibility and being capable of being arced or bowed (see FIGURE 5 Wherein it is seen that such bottommost portion maintains its stilfness and does not freely bend` When the slide fastener is in open disposition, although it may be arced or boWedV-somewhat, in contradistinction to the portion of the welts 14 and 18 which carry the elements The stifiening agent 28 may be any stiffener which Will render the welts 14 and 18 relatively stilf in the gap region 30, and may include a stilfening agent which swells up Within the welts 14 and 1'8, although the Welts 14 and 18 should be of uniform diameter throughout their lengths including both the gap region and the element carrying upper Welt portions. For example, in tapes 12 and 16 comprising cotton, With cotton cords 26, satisfactory rigidity of the welts 14 and 18 in the gap region 30 was obtained by painting such region with orange shellac. A variety of techniques could be used for applying the stiffening agent to the gap region 30, including dabbing or painting with a brush or spray. A variety of stiffening agents may be utilized including in addition to shellac. which has already been mentioned, starch solutions, varnishing solutions, and lacquer solutions. The stiffening agent should not injure the tape or cord, nor should it discolor the tape.

I have found that When the welts 14 and 18 are rendered stilf as aforesaid, the slider 22 Will not become disengaged therefrom when the slider 22 is slid from the elements 20 onto the welts 14 and 13 in the gap 30. I1 'hus, I have determined that When the welts 14 and 18 are rigid, notwithstanding their relatively small dimension compared With the outside dimensions of the elements 20, release of the slider 22 from the welts 14 and 18 is avoided. The rigidity of the gap 30 of the slide fastener of the present invention in no Way interferes With the application of the bottom stop thereto.

HThe present invention may be embodied in other specific forms Without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

I claim:

1. A slide fastener including `a slider, a pair of tapes, the innermost edges of said tapes being welted for the entire length of the tapes, mating slide fastener elements secured to said Welts in the upper portion of each of said tapes, the lower portion of each of said tapes being devoid of elements below the lowermost element on each Welt, With the element-carrying upper Welt portions being flexible, the lower Welt portions of the tapes which are devoid of elements being relatively rigid With respect to said upper Welt portions, said upper and lower Welt portions being of the same diameter, whereby the slider may be moved along said relatively rigid lower Welt portions of the tapes without becoming dislodged from the slide fastener.

2. A slide fastener in accordance with claim 1 in which the welts overlap the tapes when the elements carried by the tapes are in engaged disposition.

3. A slide fastener in accordance With claim l Wherein the lower Welt portions are impregnated With a stitfening agent.

4. A slide fastener including a pair of tapes, the innermost edges of said tapes being welted for the entire length of the tapes, mating slide fastener elements secured to said welts in the upper portion of each of said tapes, a slider, bridging means securedly joining said tapes together at the lowermost portions of said tapes, said tapes being provided with a fastener element-free gap intermediate said bridging means and the lowermost elements carried by said tapes, said gap having a length appreciably greater than the length of said slider, the welted portions of the tapes within said gap being relatively rigid compared to the relatively flexible element-carrying upper Welter portions of the slide fastener, With said slider being reciprocally movable along the welted portions in said gap and along said slide fastener elements Without becoming dislodged from the slide fastener While moving along the relatively rigid lower Welt portions of the tapes Within said gap.

5. A slide fastener in accordance with claim 4 in which the bridging means maintains the welts of the tapes in even parallel alignment in the gap portion of the slide fastener when the elements of the slide fastener are in matng engagement.

6. A slide fastener in accordance with claim 5 in which the welts of both of the tapes overlap the tapes on the same side of the slide fastener When the elements are in closed disposition.

7. A slide fastener in accordance With claim 6 in which the welted portions of the tapes are of uniform diameter throughout the length of the tapes.

8. A slide fastener in accordance with claim 7 comprising a stifi'ening agent impregnated into the welted portions in the element-free gap.

References Cited in the file of this patent UNITED STATES PATENTS l,923,262 Goebel Aug. 22, 1933 2,573,059 Rabnow Oct. 30, 1951 2,658,25l Simpson Nov. 10, 1953 2,738,560 Hug Mar. 20, 1956 FOREIGN PATENTS 570,050 Germany June 9, 1933 678,857 Great Britain Sept. 10, 1952 867,540 France Nov. 10, 1941 

